Need PN for Timing Chain, 1973 L82

[Dennis H.]

I have been researching GM OEM replacement timing components and can't seem to find a good part number for the timing chain.

Back story my 73 L82, the PO replaced the original cam and timing set with Comp Cams parts. I have the original GM OEM crank sprocket and timing chain and both are in as new condition with no visible wear. At some point in the near future I'm going to rebuild the engine back to stock as delivered from GM.

GM list the replacement cam timing sprocket as 340235 (steel) which appears to still be available but the 346261 timing chain is no longer available.

The original timing chain I have doesn't have a PN on it but the links are stamped Morse and Made in USA. Is this timing chain still available from Morse and if so is there a part number? Did GM source the timing chains from Morse? I'm assuming this is the original chain.

I understand a lot of people recommend the Cloyes True-Roller #9-3100, I'm just trying to break the code on the correct chain for the GM steel cam (340235) and crank (3896953) sprockets.

Dennis

[Patrick H.]

Re: Need PN for Timing Chain, 1973 L82

Dennis,

Why would you want to use a breakage-prone original nylon-toothed sprocket?
No matter how original you may want your engine to be, I wouldn't touch one. I have photos of one that self-destructed, in case you want to see them.

Any aftermarket chain you obtain will be better than the OEM units, if you could even find one. And, if you do, the nylon is still old.

There are several threads regarding possible replacements; often the "truck" or heavy duty ones are also recommended.

Patrick

[Dennis H.]

Re: Need PN for Timing Chain, 1973 L82

Dennis,

Why would you want to use a breakage-prone original nylon-toothed sprocket?

I'm not using the original nylon-toothed sprocket, the GM replacement sprocket is steel. I'm just trying to figure out the correct timing chain for that sprocket.

[Dennis H.]

Re: Need PN for Timing Chain, 1973 L82

This is the crank sprocket and chain I have

[Dennis H.]

Re: Need PN for Timing Chain, 1973 L82

This is an example of the GM 340235 steel cam sprocket.

[Patrick H.]

Re: Need PN for Timing Chain, 1973 L82

If you didn't buy sprocket and chain as a matched set, I'd be hesitant to buy two individual pieces and match them up.

[Dennis H.]

Re: Need PN for Timing Chain, 1973 L82

If you didn't buy sprocket and chain as a matched set, I'd be hesitant to buy two individual pieces and match them up.

Other than being sold as a set I'm not 100% sure anything is really a matched set. GM never sold anything as a matched set or set for that matter.

[Dennis H.]

Re: Need PN for Timing Chain, 1973 L82

Another Vette owner who runs the 340235 cam sprocket told me the new timing chain number is GM 14087014.

So far found I have found;
Individual Parts
Timing Chain
84-02 GM 14087014 - $45.52
Cam Sprocket
84-95 GM 340235 - $49.00

Timing Sets
Cloyes True-Roller #9-3100 - $110.99
Cloyes C-3001K - $16.99

[Ray K.]

Re: Need PN for Timing Chain, 1973 L82

Dennis,

I had to refer to some of my Chev Light Truck P & A catalogs to confirm this timing chain part number. Beginning in 1985 the #14087014 chain was the correct chain and was used in conjunction with the 340235 camshaft sprocket and the 3896953 crank sprocket for application with 350 and 305 engines. My earlier 79 -84 catalog still lists the 346261 chain. My guess this was a supplier change and thus the part number change.

Ray

[Duke W.]

Re: Need PN for Timing Chain, 1973 L82

Buy the truck OE replacement roller chain. www.napaonline.com Input the vehicle as a seventies vintage 1500 pickup. The complete set, crank and cam sprockets and roller chain costs about 30 bucks and is manufactured to the OE print, made by Cloyes. I believe the crank sprocket is steel and the cam sprocket is cast iron. NO PLASTIC!!!.

It comes in two flavors. The first has one indexing hole to place the inlet POML at the OE position. The second flavor has two additional indexing holes to either advance or retard the cam 4 degrees. The cost is about the same

I'm sure, like electrical parts, it's available under many brand names, so you can buy it at virtually any FLAPS that can cross the NAPA number to whatever brand they sell.

This chain and sprocket set will likely outlive nearly everyone on the TDB.


Duke

[James G.]

Re: Need PN for Timing Chain, 1973 L82

I just replaced the original in my 46k mile LT1 with the Cloyes double roller with the index advance retard on the crank sprocket.
Collected up a set of NOS gaskets for the pan rails and the timing cover then went at it...

I thank everyone here for the prodding as my replacement was NOT A MOMENT TOO SOON!!!
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In addition my original A1F dated balancer had slipped by approx 30 degrees and laterally rearward about 1/16"
Off to damper doctors for a rebuild!
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